Technological Field
The present invention relates to an image processing apparatus such as an MFP (Multi-Functional Peripheral) and its relevant technique.
Description of the Related Art
There is an image processing apparatus (an MFP or the like) having an image processing function regarding printing, scanning and/or the like.
In recent years, such an image processing apparatus (an MFP or the like) is required to serve as a server device in a network, and there is also an MFP provided with a server function. In this MFP, the server function and the image processing function are achieved simultaneously in parallel in a multitasking OS environment.
Such an MFP, however, has difficulty in being provided with a broadband memory (with large transmission capacity) (and high capacity) that a general server has, because of cost constraint and the like, and only has a memory sufficient to achieve the image processing function for MFP.
In such a device environment, in a case where both an operation regarding the server function of the MFP (also referred to as a server operation) and an operation regarding the image processing function of the MFP (also referred to as an MFP operation) are performed in parallel in the MFP, there arises contention on the memory.
In a case, for example, where the above two operations are performed in parallel while a relatively large memory bandwidth is used for the server operation, the memory bandwidth which can be used for the MFP operation sometimes consequently becomes smaller. As a result, the time required to perform the MFP operation increases and a user's waiting time also increases. In more detail, when a user intends to perform a copy or print operation, the required time becomes longer than usual and the user feels uncomfortable.
Then, it is an object of the present invention to provide a technique capable of effectively using a memory shared by an image processing apparatus which performs a server function and an image processing function in parallel, to thereby suppress a delay in an operation regarding the image processing function.
Japanese Patent Application Laid Open Gazette No. 2009-271944 (Patent Document 1) discloses an arbitration device which is intended to ensure a required bandwidth for two types of access masters, a local concentration access master and a fixed rate access master. When the arbitration device receives an access request not below the bandwidth allocated in advance from the local concentration access master, the arbitration device permits the request in a first period which is set in advance. Then, in a second period after the first period is ended, the access request from the local concentration access master is masked and the access by the fixed rate access master is performed.
The technique disclosed in Patent Document 1, however, does not relate to the contention between the server operation and the MFP operation. Further, even if the MFP operation is performed by the local concentration access master and the server operation is performed by the fixed rate access master in the technique disclosed in Patent Document 1, when the bandwidth for the MFP operation exceeds a certain degree (the bandwidth allocated in advance), it is impossible to ensure the bandwidth for the MFP operation especially after the first period. As a result, the required time for the MFP operation increases and the user's waiting time also increases.